4 research outputs found
Ionospheric response modeling under eclipse conditions: Evaluation of 14 December 2020, total solar eclipse prediction over the South American sector
In this work, we evaluate the SUPIM-INPE model prediction of the 14 December 2020, total solar eclipse over the South American continent. We compare the predictions with data from multiple instruments for monitoring the ionosphere and with different obscuration percentages (i.e., Jicamarca, 12.0°S, 76.8°W, 17%; TucumĂĄn 26.9°S, 65.4° W, 49%; ChillĂĄn 36.6°S, 72.0°W; and BahĂa Blanca, 38.7°S, 62.3°W, reach 95% obscuration) due to the eclipse. The analysis is done under total eclipse conditions and non-total eclipse conditions. Results obtained suggest that the model was able to reproduce with high accuracy both the daily variation and the eclipse impacts of E and F1 layers in the majority of the stations evaluated (except in Jicamarca station). The comparison at the F2 layer indicates small differences (<7.8%) between the predictions and observations at all stations during the eclipse periods. Additionally, statistical metrics reinforce the conclusion of a good performance of the model. Predicted and calibrated Total Electron Content (TEC, using 3 different techniques) are also compared. Results show that, although none of the selected TEC calibration methods have a good agreement with the SUPIM-INPE prediction, they exhibit similar trends in most of the cases. We also analyze data from the Jicamarca Incoherent Scatter Radar (ISR), and Swarm-A and GOLD missions. The electron temperature changes observed in ISR and Swarm-A are underestimated by the prediction. Also, important changes in the O/N2 ratio due to the eclipse, have been observed with GOLD mission data. Thus, future versions of the SUPIM-INPE model for eclipse conditions should consider effects on thermospheric winds and changes in composition, specifically in the O/N2 ratio
Variations of total electron content during a magnetic storm
En este trabajo se analizan las variaciones del Contenido Electrónico Total (CET) durante una tormenta geomagnética, calculado a partir de mediciones del retardo ionosférico sobre las señales de código y fase, transmitidas por los satélites del Sistema de Posicionamiento Global (SPG).
Los datos procesados corresponden a la estaciĂłn SPG perteneciente al proyecto CAP (Central Andes Project), situada en San Miguel de TucumĂĄn (26° 53â S , 65° 13â W), Argentina.
Las variaciones del CET ocurridas en los dĂas de abril de 1997 presentan valores altos, comparados con valores promedios del mes de abril calculados con mediciones de nuestro banco de datos de años anteriores.
El fenĂłmeno se registrĂł con mayor intensidad en el perĂodo comprendido entre los dĂas 9 al 12 de abril de 1997, tomando un valor de Kp=7- (Figure 2) para el dĂa 11.
AdemĂĄs se comparĂł dichos valores con los obtenidos para dĂas anteriores y posteriores a la tormenta.
Los valores de CET alcanzados durante la tormenta exceden en un 30 % a los valores que se alcanzan para dĂas calmos durante esa Ă©poca del año, lo cual provoca mayores errores en el cĂĄlculo del posicionamiento mediante el sistema SPG.
doi: https://doi.org/10.22201/igeof.00167169p.2002.41.1.26
Longitudinal variations of ionospheric parameters near totality during the eclipse of December 14, 2020
On December 14, 2020, a total solar eclipse occurred whose shadow cone projected over part of South America. Its effect on critical ionospheric frequencies variability is analysed, considering two stations with similar geographical latitudes and a 95% obscuration percentage: ChillĂĄn (36.6°S, 72.0°W), in Chile, and BahĂa Blanca (38.9°S, 62.2°W), in Argentina. A comparison of the ionospheric response to the eclipse is made with quiet time daily values and the IRI-2016 model. Results indicate that the greatest eclipse impacts are obtained in foE and foF1, with âŒ31% and âŒ40% of maximum reductions, respectively. Alternatively, weak disturbances are observed in the foF2 case (<20%). The recombination coefficients were calculated for the E- layer and F1-layer with values of α âŒ10â9 cm3 sâ1 and for F2-layer with values in ÎČ âŒ10â4 sâ1, similar to previous studies. Longitudinal differences between both ionospheric stations are very small for the F1-layer (âŒ11%), but a much larger variability is found at F2-layer critical frequencies (âŒ20%). These results suggest different plasma diffusion processes at high altitudes in the different locations that require further investigation in future studies.Fil: de Haro BarbĂĄs, Blas Federico. Universidad Nacional de TucumĂĄn. Facultad de Ciencias Exactas y TecnologĂa. Departamento de FĂsica; ArgentinaFil: Bravo Sepulveda, Manuel Alejandro. Universidad de ConcepciĂłn; ChileFil: Elias, Ana Georgina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - TucumĂĄn; Argentina. Universidad Nacional de TucumĂĄn. Facultad de Ciencias Exactas y TecnologĂa; ArgentinaFil: MartĂnez Ledesma, Miguel. Universidad de ConcepciĂłn; Chile. Centro Interuniversitario de FĂsica de la Alta AtmĂłsfera; ChileFil: Molina, Maria Graciela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - TucumĂĄn; Argentina. Universidad Nacional de TucumĂĄn. Facultad de Ciencias Exactas y TecnologĂa; ArgentinaFil: Urra, B.. Centro Interuniversitario de FĂsica de la Alta AtmĂłsfera; ChileFil: Venchiarutti, JosĂ© ValentĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - TucumĂĄn; Argentina. Universidad Nacional de TucumĂĄn. Facultad de Ciencias Exactas y TecnologĂa. Departamento de FĂsica; ArgentinaFil: Villalobos, C.. Centro Interuniversitario de FĂsica de la Alta AtmĂłsfera; Chile. Universidad Adventista de Chile; ChileFil: Namour, Jorge Habib. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - TucumĂĄn; Argentina. Universidad Nacional de TucumĂĄn. Facultad de Ciencias Exactas y TecnologĂa. Departamento de FĂsica; ArgentinaFil: Ovalle, ElĂas M.. Centro Interuniversitario de FĂsica de la Alta AtmĂłsfera; Chile. Universidad de ConcepciĂłn; ChileFil: Guillermo, Eduardo Daniel. Universidad TecnolĂłgica Nacional. Facultad Regional BahĂa Blanca; ArgentinaFil: Carrasco, E.. Universidad de ConcepciĂłn; ChileFil: de Pasquale, Lorenzo. Universidad TecnolĂłgica Nacional. Facultad Regional BahĂa Blanca; ArgentinaFil: Rojo, E.. Centro Interuniversitario de FĂsica de la Alta AtmĂłsfera; Chile. Universidad Adventista de Chile; ChileFil: Leiva, R.. Centro Interuniversitario de FĂsica de la Alta AtmĂłsfera; Chile. Universidad Adventista de Chile; Chil
DataSheet1_Ionospheric response modeling under eclipse conditions: Evaluation of 14 December 2020, total solar eclipse prediction over the South American sector.pdf
In this work, we evaluate the SUPIM-INPE model prediction of the 14 December 2020, total solar eclipse over the South American continent. We compare the predictions with data from multiple instruments for monitoring the ionosphere and with different obscuration percentages (i.e., Jicamarca, 12.0°S, 76.8°W, 17%; TucumĂĄn 26.9°S, 65.4° W, 49%; ChillĂĄn 36.6°S, 72.0°W; and BahĂa Blanca, 38.7°S, 62.3°W, reach 95% obscuration) due to the eclipse. The analysis is done under total eclipse conditions and non-total eclipse conditions. Results obtained suggest that the model was able to reproduce with high accuracy both the daily variation and the eclipse impacts of E and F1 layers in the majority of the stations evaluated (except in Jicamarca station). The comparison at the F2 layer indicates small differences (<7.8%) between the predictions and observations at all stations during the eclipse periods. Additionally, statistical metrics reinforce the conclusion of a good performance of the model. Predicted and calibrated Total Electron Content (TEC, using 3 different techniques) are also compared. Results show that, although none of the selected TEC calibration methods have a good agreement with the SUPIM-INPE prediction, they exhibit similar trends in most of the cases. We also analyze data from the Jicamarca Incoherent Scatter Radar (ISR), and Swarm-A and GOLD missions. The electron temperature changes observed in ISR and Swarm-A are underestimated by the prediction. Also, important changes in the O/N2 ratio due to the eclipse, have been observed with GOLD mission data. Thus, future versions of the SUPIM-INPE model for eclipse conditions should consider effects on thermospheric winds and changes in composition, specifically in the O/N2 ratio.</p